Rotary internal-combustion engine.



M. A. T. HOFFMANN. ROTARY INTERNAL COMBUSTION ENGINE.

APPLICATION FILED AUG. 19. 1912.

Patented Dec. 22, 1914.

ence being had MATHIAS A. '1. HOFFMANN, 0F CAMIIBELLSPORT, WISCONSIN.

ROTARY INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Dec. 22, 1914;.

Application flied August 19, 1912. Serial No. 715,804..

T 0 all whom it may concern:

Be it known that I, MATHIAB Manx. a citizen of the United States, andresident of Campbellsport, in the county of Fond du Lac and State ofWisconsin, have invented new and useful Improvements in RotaryInternal-Combustion Engines, of which the following is a description,referto the accompanying drawings, which are a part of thisspecification.

This invention relates to improvements in rotary internal combustionengines of that type in which the carbureted mixture is received withinthe engine chambers, is compressed, ignited and burned, and-the burntgases are discharged from the chambers after they have performed theirwork.

It -is one of the objects of the present invention to provide a rotaryinternal coinbustion engine having a piston which rotates continuouslyin one direction and receives an impulse every quarter revolution ofsaid piston.

A further object of the invention is to provide a rotary internalcombustion engine with a rotary member having slidable pistons which areconstructed in a novel manner and are provided with means for formiiiggas tight joints in the chambers of which they form a part.

A further object of the provide a rotary internal combustion enginewhich is simple in construction, is eflicient in operation, and is welladapted for the purpose desired.

\Vith the above and other objects in View, the invention consists of theimproved rotary internal combustion engine and parts and combinations,as set forth in the claim. and all equivalents thereof.

In the accompanying ,drawing, in which the same reference charactersindicate the same parts in all of the views: -F-igure 1 is alongitudinal vertical sectional view of the improved rotary internalcombustion engine; Fig. 2 is a transverse sectional view thereof takenon line 2-2 of Fig. 1; Fig. 3 is a fragmentary detail view of the outerjoint of one of the slidable pistons; and Fig. -l is a similar view ofthe inner joint thereof.

Referring to the drawing the numeral 8 indicates the outer casin orcylinder of the improved rotary interna combustion engine and 9 thewater chamber or cooling means thereof. The cylinder is of ellipticalform in cross section with its greatest length in A. T. Horr- 12approximately invention is to I its parts connected together horizontalplane and the opposite ends of the cylinder are closed by cylinder heads10 bolted thereto. A shaft 11, passing centrally through the cylinderheads and through stufiing boxes 12 formed on the heads, has keyedthereto a piston member annular in form. The outer end portions of theshaft are reduced in diameter to form the shoulders 13 against whichcollars 14 bear and to receive the soft metal packing sleeves 15 mountedthereon. The peripheries of these sleeves are tapered slightly'to enterthe tapered recesses 16 of the stufiing nuts 17 and the nuts 17 arethreaded into the tubular bosses 18 of the heads to form tight bearingsbetween the.

shaft and the heads.

The opposite end portions of the piston member have recesses 19 formedtherein to accommodate the elliptical cams 20 projecting inwardly fromthe cylinder heads 10. These cams are curved concentrically withrelation to the elliptical form of the cylinder. The piston member isprovided with four piston slots 21 extending radially from the hub 22 ofthe piston member to the periphery thereof, and pistons 23, slidably andyieldingly positioned within said slots, are adapted to bear against theinner periphery and the inner faces of the cylinder heads and form fourseparate cylinder chambers 24, 25, 26 and 27 respectively. While thesechambers constantly change and merge into one another while the pistonmember is rotating, they are indicated by different numerals forconvenience of description.

Each slidable piston is formed in two by tongue and grooved joints 28and coiled springs 29 interposed between the two parts serve toyieldingly press the outer ends of the parts against the cylinder headsand form a tight joint. The portions of the piston parts adjacent to thecylinder heads areprovided with recesses 30 in which slide blocks 31,

having rollers .32 journaled therein, bear against the elliptical cams20 of the cylinder heads. Coiled springs 33 within these recesses andbearing against the slide blocks force the outer rounded edge of thepiston against the inner surface of the cylinder. The opposite endportions of the piston member are provided with annular grooves 34 toaccommodate piston rings 35 positioned therein.

The engine receives its carbureted gas pipe 36 and exhausts through thepipe 37 on the opposite side of the cylinder. The pipe 38 provides thecooli ng water for the water chamber and the pipe 39 receives thedischarge therefrom. Spark plugs 4-0, extending into the pockets 41 ofthe cylinder heads, provide for igniting the charge within the cylinder.These plugs are mounted in the upper opposite end portions of thecylinder and are adapted'to ignite the charge when under pressure.

In operation with the piston 'member, turning in the direction indicatedby the arrow and the parts in the position shown in *ig. 2, the chargewill be drawn into the chamber 24 as the chamber increases in size withthe rotation of the piston member. When the said chamber has increasedto the greatest extent it will be closed by the piston forming the rearWall of said chamber pass ing by the inlet pipe and as indicated by thechamber 25. The further movement of the piston will compress the chargeand when compressed to the extent indicated in the chamber 26 the chargewill be ignited and the burning and expanding gases will react againstthe piston forming the advancing wall of this chamber and rotate thepiston member to the right (in Fig. 2), due to the fact that the pistonforming the said advancing Wall is extended from the piston member agreater distance than the piston following. As the piston membercontinues to rotate the chamber will increase in size until the chamberreaches the position indicated by the chamber 27, when the said chamberwill be in communication with the exhaust opening and the spent gasesdisthrough the intake charged therefrom. This cycle of operation willcontinue in the same manner during the rotation of the rotary member.

The construction advanced or retarded as desired.

From the foregoing description it willbe seen that the rotar'y internalcombustion engine is of simple construction and is well adapted for thepurpose desired.

What I claim as my invention is:

A rotary internal combustion engine, comprising a cylinder elliptical incross section and having inlet and outlet openings, heads closing theends of said cylinder and provided with inwardly projecting camsapproximately concentric With the elliptical portion of the cylinder, ashaft extending through the heads, a piston member mounted on the shaftand positioned within the cylinder and having end recesses into whichthe cams project, said piston member also provided with radial slots,pistons slid-ably positioned Within the slots and bearing against thecylinder and the heads and dividing the cylinder into a number ofchambers, the inlet and outlet openings of said cylinder communicatingwith the chambers,

said pistons provided with slidable blocks v having rollers which rideon the cams, and

springs interposed between the pistons and the slidable blocks toyieldingly mount the pistons upon the cams.

In testimony" whereof, I afiix my signature, in presence of twowitnesses.

MATHIAS A. T. HOFFMANN. Vitnesses:

LEO A. I'IOFFMANN, J. H. KLEINHANS.

permits the spark to be

